GM concept car, the EN-V or "Electric Networked-Vehicle," is driven at a launch ceremony held at the Shanghai Pudong Expo in China, Wednesday, March 24, 2010. AP

The BMW i3 electric compact car aimed at people in megacities where exhaust emissions are a concern. The company used carbon fiber in the vehicle’s construction to keep weight down and help improve driving performance and range. Marijan Murat/dpa/AP

Vehicle (301) ECOCAR8E, Prototype, running on Battery Electric, competing for IUTVA, is seen racing in competition during day two of the Shell Eco-marathon Challenge Europe at The Ahoy centre in Rotterdam, The Netherlands, May 17, 2012.Shell/AP

A visitor looks at Toyota Motor Co.'s Camatte 57s electric car displayed at the Tokyo Toy Show in Tokyo, June 13, 2013. Toyota designed the three-seater concept car for children to drive only on private property. Koji Sasahara/AP

A DOK-ING car, a small Croatian three-seat electric city concept car, is seen at the LA Auto Show in Los Angeles, California, November 17, 2011. Lucy Nicholson/Reuters

Members of the TUM CREATE group ride a prototype of their electric-powered VOI scooter at the Nanyang Technological University in Singapore, May 28, 2013. Edgar Su/Reuters

A father helps his son drive a kids electric car in a pleasure ground in Dafeng, in east China's Jiangsu province, April 5, 2010. Alexander F. Yuan/AP

A MG Midget electric car is driven during the "Electric Car Rally from Tallinn to Monte Carlo" event, in Tallinn, Estonia, June 2, 2011. Ints Kalnins/Reuters

Car2go brings North America's first all-electric car sharing network to San Diego. Car2Go is a subsidiary of Daimler AG that provides car sharing services in several cities in Europe and North America. In November 2011 the world's first all-electric carsharing network was launched in San Diego, California, with a fleet of 300 Smart EDs. PRNewsFoto

A driver drives the latest version of "MyCar", an electric car made by the Hong Kong Polytechnic University, inside the university campus in Hong Kong January 30, 2012. Tyrone Siu/Reuters

A government employee drives an electric Jeepney at a charging station in Manila's Makati financial district January 30, 2012. Traditional Jeepneys are the most popular means of public transportation in the Philippines. They were originally made from US military jeeps left over from World War II and are known for their flamboyant decoration and crowded seating. Erik De Castro/Reuters

Tesla workers cheer on one the first Tesla Model S cars sold during a rally at the Tesla factory in Fremont, Calif. Paul Sakuma/AP

(L. to r.) Vectrix Team (Germany) Orlikon Solar Racing Team (Switzerland) and Team Trev (Australia) pose in the flags alley before the start of the Zero Race in front of the United Nations European headquarters in Geneva August 16, 2010. Teams from three continents took part in the longest and greenest race with their electric cars. Denis Balibouse/Reuters

A parking station for the Autolib' electric car-share scheme is seen on a street in Paris, Dec. 2, 2011. Paris, in its latest bid to be an innovator of the City of Tomorrow, is launching an electric car-sharing program to cut air and noise pollution on the city's medieval cobblestone streets and beyond. Christophe Ena/AP

Electric car company Tesla has taken the wraps off of its first SUV, The Model X. Unveiling it Thursday night at the company's design studio in southern California, Tesla CEO Elon Musk says the Model X will "redefine the upscale SUV market."